Single-Shot Visualization Of Evolving Laser- Or Beam-Driven Plasma Wakefield Accelerators

We introduce Frequency-Domain Tomography (FDT) for visualizing sub-ps evolution of light-speed refractive index structures in a single shot. As a prototype demonstration, we produce single-shot tomographic movies of self-focusing, filamenting laser pulses propagating in a transparent Kerr medium. We then discuss how to adapt FDT to visualize evolving laser-or beam-driven plasma wakefields of current interest to the advanced accelerator community. For short (L similar to 1 cm), dense (n(e) similar to 10(19) cm(-3)) plasmas, the key challenge is broadening probe bandwidth sufficiently to resolve plasma-wavelength-size structures. For long (L similar to 10 to 100 cm), tenuous (n(e) similar to 10(17) cm(-3)) plasmas, probe diffraction from the evolving wake becomes the key challenge. We propose and analyze solutions to these challenges.Physic

Vacuum Energy Density and Cosmological Constant in dS Brane World

We discuss the vacuum energy density and the cosmological constant of dS$_5$ brane world with a dilaton field. It is shown that a stable AdS$_4$ brane can be constructed and gravity localization can be realized. An explicit relation between the dS bulk cosmological constant and the brane cosmological constant is obtained. The discrete mass spectrum of the massive scalar field in the AdS$_4$ brane is used to acquire the relationship between the brane cosmological constant and the vacuum energy density. The vacuum energy density in the brane gotten by this method is in agreement with astronomical observations.Comment: 16 pages,4 figure

Grazing activity increases decomposition of yak dung and litter in an alpine meadow on the Qinghai-Tibet plateau

Publishe

Investigation of the energy dependence of the orbital light curve in LS 5039

LS 5039 is so far the best studied $\gamma$-ray binary system at multi-wavelength energies. A time resolved study of its spectral energy distribution (SED) shows that above 1 keV its power output is changing along its binary orbit as well as being a function of energy. To disentangle the energy dependence of the power output as a function of orbital phase, we investigated in detail the orbital light curves as derived with different telescopes at different energy bands. We analysed the data from all existing \textit{INTEGRAL}/IBIS/ISGRI observations of the source and generated the most up-to-date orbital light curves at hard X-ray energies. In the $\gamma$-ray band, we carried out orbital phase-resolved analysis of \textit{Fermi}-LAT data between 30 MeV and 10 GeV in 5 different energy bands. We found that, at $\lesssim$100 MeV and $\gtrsim$1 TeV the peak of the $\gamma$-ray emission is near orbital phase 0.7, while between $\sim$100 MeV and $\sim$1 GeV it moves close to orbital phase 1.0 in an orbital anti-clockwise manner. This result suggests that the transition region in the SED at soft $\gamma$-rays (below a hundred MeV) is related to the orbital phase interval of 0.5--1.0 but not to the one of 0.0--0.5, when the compact object is "behind" its companion. Another interesting result is that between 3 and 20 GeV no orbital modulation is found, although \textit{Fermi}-LAT significantly ($\sim$18$\sigma$) detects LS 5039. This is consistent with the fact that at these energies, the contributions to the overall emission from the inferior conjunction phase region (INFC, orbital phase 0.45 to 0.9) and from the superior conjunction phase region (SUPC, orbital phase 0.9 to 0.45) are equal in strength. At TeV energies the power output is again dominant in the INFC region and the flux peak occurs at phase $\sim$0.7.Comment: 7 pages, 6 figures, accepted for publication in MNRA

Geology and mineralization of the Mt Carbine Tungsten Deposit, Northern Queensland, Australia

The Mt Carbine quartz-wolframite-scheelite sheeted vein deposit is located ~80 km NW of Cairns, Northern Queensland. It was the largest vein type W deposit in Australia and accounted for 43% of Australia’s annual W production in 1986, prior to closure because of international Sn-W market crash. The hard rock resources at Mt Carbine include indicated resources of 18 Mt at 0.14% WO3 and inferred resources of 29.3 Mt at 0.12% WO3 (Carbine Tungsten Limited Annual Report 2014). The vein system in Mt Carbine is hosted in Ordovician to Devonian Hodgkinson Formation metasedimentary rocks, which include turbiditic metasediments composed mainly of greywacke, siltstone-shale, slate, basalt, conglomerates and chert. There are four 30-40 m wide vein zones in the open pit with different orientations, with Zones 1 - 3 being ~300°/80° (strike/dip) with dip direction of 210°, 210° and 20°, respectively, and Zone 4 270°/65° with dip direction of 180° to 185°. Based on drill core logging and open pit observation, the paragenesis sequence has been established. Stage 0 is represented by deformed curvy and discontinuous quartz-dominant veins with minor to none W mineralization. Stage I continuous quartz-dominant veins have straight and continuous margin, and are composed of wolframite±scheelite± K-feldspar±biotite±tourmailine±apatite. Stage II veins are straight & continuous, quartz-dominant with sharp boundaries, and contain chlorite±scheelite±wolframite± cassiterite±muscovite. Stage III is represented by undeformed straight and continuous quartz±chlorite± muscovite±molybdenite±arsenopyrite±chalcopyrite±pyrite± pyrrhotite±sphalerite veins, without W mineralization. Stage IV veins are featured by the undeformed straight and continuous shape and quartz ± calcite ± fluorite mineralogy without any W mineralization. The W mineralization is mostly in stage II quartz veins, with less economic W mineralization in the other 3 stages of veins. Ore minerals are wolframite and scheelite. Wolframite is typically euhedral and occurs in quartz veins, while the occurrences of scheelite are: (1) euhedral grains in quartz vein and, (2) pseudomorphing wolframite grains or cutting across wolframite grains as veinlets. There are at least 3 felsic igneous rock types in the mining district, including porphyritic biotite granite, equigranular coarse-grained biotite granite and fine-grained felsic dykes that cuts across the ore body. There is no observable contact between granite and the W veins, thus their relationship is unclear. Mineralized quartz veins and chlorite alteration occur in the porphyritic biotite granite, whereas no quartz vein and alteration are present in the fine-grained felsic dyke, indicating that the porphyritic biotite granite was earlier than mineralization and the felsic dyke later than mineralization. This observation is consistent with the latest dating results: the LA-ICP-MS zircon U-Pb age of the porphyritic biotite granite is 298±3 Ma and the felsic dyke 261±7 Ma, whereas the molybdenite Re-Os age from the mineralized quartz vein is 28 ±1 Ma, and the muscovite 40Ar-39Ar ages are 282-277 (±1-2) Ma. There is no overlap between the 2 muscovite 40Ar-39Ar ages, probably indicates there was some post-mineralization tectono-thermal activities. Preliminary fluid inclusion studies reveal that most of them are primary, with sizes up to 26 μm. The homogenization temperatures range from 210 to 290°C, final ice-melting temperatures are between 0 and −3.7°C. Laser Raman analysis identified CH4 in the vapor bubble. The δ34S values of sulphides range from -9.1 to -6.0‰, and O-H isotopes largely overlap with metamorphic water